Another anesthesiologist who is unaware about kind of medication, will evaluate the patients for severity of stridor. We will record the vital sings and grade of stridor every 6 hour. Respiratory rate (RR), heart rate (HR), blood pressure (BP) and oxygen saturation (SPO2) were recorded for each patient immediately before aerosol administration (time 0) and at 30 and 60 min; and 2,4,8,12,24,36 and 48 hrs. After extubation then the presence of stridor (heard with the aid of stethoscope) was recorded within 48 hr of extubation